Forgive me for asking a question that may have already been asked, or beaten to death, but what is preventing Python from requiring libffi as an external/required dependency, rather than keeping it and taking on the burden of fixes/backporting in lieu of updates or pending releases from upstream?

Historically (at least the last ~2-3 years), libffi in Python has been plagued with, at least:

* Inconsistent / incorrect merging of libffi fixes (including regressions)
* Unsolved issues in vendored copy that have been fixed/released upstream
* Complex, manual and error-prone updates to vendored copy
* Lack of regular maintenance, from what largely appears to be a lack of knowledge about, or confidence in updating the vendored copy (fear of breakage)

I know at least FreeBSD currently requires --sytem-libffi for i386 systems in certain versions due to issue 22521 (issue 23042) and there are currently 50 open issues matching libffi (granted not all of them will be root-caused by libffi internal). I note that number to highlight the maintenance requirement.